In power receiving facilities, a closed type distributor (called a switchgear) is provided in which a vacuum circuit breaker for breaking load current or accident current, a disconnecting switch and earth switch for ensuring safety of an operator in maintaining the load, a detector for system voltage and current, a protection relay, and the like are contained.
There are various insulation methods for switchgears. Solid insulation, compressed air insulation, full vacuum insulation, and the like have appeared in recent years in view of environment, in addition to a conventional air insulation panel and cubicle GIS using SF6 gas. Downsizing of components of the breaker, disconnecting switch, and earth switch has been accelerating in various insulation methods. A switchgear (intensive type switchgear) in which a vacuum valve integrating circuit breaking, disconnecting, and earthing functions in a single container is stored in an insulation gas container, has been suggested (for example, see Patent Document 1).
[Patent Document 1] JP-09-153320-A